Beige Food Three
Ultra-processed Food: The Next Evolutionary Leap for Humans
I have brought up my concept of ultra-processed foods and evolution in two previous pieces: Science of Fat in Context and Food Fears One.
“Evolutionary fitness is exclusively defined by the ability to pass those genes along (procreation). That we didn’t have ultra-processed foods in Paleolithic times is as true as the fact that early hominins had to spend 6-8 hours chewing raw food to extract sufficient energy to survive. If you’ve read Dr. Richard Wrangman’s work (book: Catching Fire) then you know that our big brains and small guts could not be supported with raw food. It was the ability of hominin ancestors to make additional energy available through cooking that is likely largely responsible for the presence of Homo sapiens on the planet now.
Except for the fact that ultra-processed foods will not be around long enough to have an impact on our further central nervous system development (because petroleum and its by-products are a finite resource— necessary in ultra-processed food production), we might have experienced our next great evolutionary leap as a result… [But as of today] we’re the only animals on the planet optimized for the net energy benefits of eating cooked food over raw.” [1]
The most valuable aspect of ultra-processed foods to humans is enhanced net energy. When we consume food, it’s not energy. Food contains energy that can only be accessed through digestion.
In the absence of entire gastrointestinal, immune, neurotransmitter/hormonal systems, things we define as food cannot become the energy that sustains life. Grass is food to a creature with four stomachs; but it has no energy potential for human animals who lack enough digestive organs to access the constituents within grass that could support our biological pathways
I go into some detail on how ineffective animal studies are for identifying what constitutes appropriate food for humans in Food Fears One:
“Our food consumption is one area where animal studies are particularly inapplicable. We have no other animal on which to experiment that is optimized for cooked food consumption and therefore results are not readily transferrable to our experience. A perfect example of the misapplication of animal studies in identifying our relative health risks is the appearance of carcinogens in food as a result of cooking it.”
Humans have evolved to use cooked food to access energy for their systems. In fact, we have evolved to such a degree we are no longer able to sustain our living systems exclusively with raw food as other animals do.
Cooking breaks down the constituent parts of the food prior to consumption so that our gastrointestinal, neurotransmitter/hormone and immune systems don’t work as hard to extract the chemicals and trace elements (the energy) needed for our biological systems to function.
Ultra-processed foods make even more of those constituent parts available and it means our entire digestive process has even less to do to make energy available to our living system.
We are not evolutionarily optimized for ultra-processed foods (yet) as they haven’t been on the scene for a few hundred thousand years. However, many types of humans benefit greatly from that highly-accessible energy of ultra-processed foods today, even in the absence of us having evolved to be wholly optimized for them at that moment.
Running the digestive, immune and neurotransmitter/hormonal systems in the body takes energy. When you consume a piece of home-cooked lasagna, some of the energy within that food has to be used just to access the energy within the food. If you say that piece of lasagna is 550 kilocalories, then you would naturally assume you’ve consumed that much energy. Kilocalories or calories (they’re interchangeable) are the unit of measure used for the energy contained within the food.
But in fact, there’s no absolute way to know how much energy your body extracted from that food. It’s estimates and averages from start to finish. The challenge with estimates and averages is when there is variance outside those numbers, the variance is pathologized rather than accepted as an inherent limitation of the original estimates and averages in the first place.
“TEE [total energy expenditure] in humans and other primates has traditionally been viewed as a simple product of body size and activity level (FAO et al. 2001). Although this perspective persists in some areas of ecology and public health, a large and increasing set of studies from free-living populations across a broad range of populations and species provides a much more dynamic and complex view of our metabolic physiology.”
You could feasibly eat that slice of lasagna and have a net energy deficit — meaning your body used energy to try to extract the constituent chemicals and trace elements (energy) and yet it somehow failed to access that energy in the end. How? Well perhaps you have primary lactose intolerance and the cream used in the lasagna meant your digestive system was doing all the work to try to extract the energy all while your lack of lactase meant you spent the rest of the night on the toilet and all of those valuable constituent parts hightailed it out before you were able to access them.
If you have undiagnosed active celiac disease, you could eat gluten to a point where next to no energy can be extracted from any food you eat because your immune system’s reaction to the presence of gluten has destroyed the villi in your intestines that are needed to help with nutrient absorption.
I have given these two possibilities as more extreme examples, but far more likely is there will be variation in the net energy extracted from a piece of lasagna for an otherwise healthy individual just because a dynamic complex living system adjusts on the fly all the time as the external and internal environments shift.
“Age-related biological differences and women’s hormonal fluctuations can introduce variability into clinical trial data, adding complexity and potentially increasing costs,” Suarez-Rizzo explains.”
That women are not studied because they can introduce variability in a clinical trial is also why the variability that women experience can result in them applying clinical trial data that cannot be applied to them. It means that what is a natural variation in the net energy extracted by an individual female is less understood because it is less studied.
When you have any chronic condition, including an eating disorder, then net energy is critical for supporting any recovery or symptom management effort. The food you take in is only one half of the equation to calculate net energy. Unfortunately, the best we can do with the other half of the equation is hit averages and estimates for what energy must be used to break down the food to its useable parts. Those estimates are going to be more accurate for healthy males, less accurate for females and decidedly off the mark for most with chronic conditions, especially conditions that affect the body’s ability to generate and/or regulate energy production and use.
Image in outline preview: Flickr.com Rafael Edward.
Pontzer H. Energy expenditure in humans and other primates: a new synthesis. Annual Review of Anthropology. 2015 Oct 21;44:169-87.
Gholam D, Wiebe J. The importance of equal representation in clinical trials.
